Oncogenes and bladder cancer.

We screened a series of 15 superficial and invasive transitional cell carcinomas of the bladder for transforming activity on the NIH/3T3 transfection assay. In addition, by obtaining tumour DNA and normal lymphocyte DNA from the same patients we looked for evidence of gene amplification or rearrangement of the c-H-ras-1 gene by Southern blot analysis. One patient (with a grade 2T1 tumour) was shown to have an activated oncogene on the NIH/3T3 transfection assay and this was identified as a c-H-ras-1 gene. We could find no evidence of gene amplification or rearrangement of this gene in any tumour. The significance of activation of ras oncogenes in the pathogenesis of human bladder carcinoma is unclear.